Composition and antimicrobial activity of Cymbopogon giganteus (Hochst.) chiov. essential flower, leaf and stem oils from cameroon

The essential oils of fresh flowers (2 samples), leaves and stems of Cymbopogon giganteus (Hochst.) Chiovenda from Cameroon were investigated by GC and GC/MS. More than 55 components have been identified in the samples 1 (flowers 1), 2 (leaves), 3 (stems) and 4 (flowers 2) with main compounds possessing the p-menthadiene skeleton as follows: cis-p-mentha-1(7),8-dien-2-ol (1: 22.8%, 2: 27.7%, 3: 29.1%, 4: 20.5%), trans-p-mentha-1(7),8-dieii-2-ol (1: 24.9%, 2: 21.6% 3: 28.1%, 4: 26.5%), trans-p-mentha-2,8-dien-1-ol (1: 17.3%, 2: 22.1%, 3: 21.4%, 4: 16.3%) and cis-p-mentha-2,8-dien-1-ol (1: 8.3%, 2: 5.4%, 3: 4.6%, 4: 9.7%). Additional components in higher concentrations, responsible for the characteristic aroma impressions of these samples are especially limonene, trans-verbenol and carvone as well as some other mono- and sesquiterpenes. Antimicrobial activities of the four oils were found against Gram-(+)- and Gram-(-)-bacteria as well as the yeast Candida albicans, and these results were discussed with the compositions of each sample.